Our objective is to identify bladder tumor-associated antigens (BTAA) in human urinary bladder cancer. Heteroantisera is being raised in rabbits against BTAA prepared from hypotonic saline extracts, chromatographic antigenic fractions and whole carcinoma cells of fresh tumor or cultured bladder carcinoma cells. Following extensive absorption with lyophilized normal adult tissues, erythrocyte stroma and plasma, the specificity of the reaction of the antisera to bladder tumors is being tested using Ouchterlony immunodiffusion, immunoelectrophoresis, microcytotoxicity and immunofluorescent techniques. Cross reactivity of the BTAA antisera against various histologic types and grades of bladder carcinomas, extravesicular malignancies and embryonic antigens is being assessed using the appropriate above techniques. Heteroantisera to normal bladder urothelium-specific antigens (BUSA) is also being raised against saline extracts and chromatographic fractions of normal human bladder urothelium. BTAA and BUSA is being quantified in tissues containing various bladder lesions using immunofluorescence. The results of these immunological studies will be correlated with the histopathologic appearance, stage and progression of the bladder tumors. BIBLIOGRAPHIC REFERENCES: Purtilo, D.T., Cassel, C., Yang, J.P.S., Stephenson, S.R., Harper, R., Landing, B.H. and Vawter, G.F.: X-linked Recessive Progressive Combined Variable Immunodeficiency (Duncan's Disease). The Lancet I:935-941, 1975. Purtilo, D.T., Riggs, R.S., Evans, R. and Neafie, R.C.: Serum Immunoglobulin Concentrations of Parasitized Malnourished Children. Am. J. Trop. Med. Hyg. March, 1976.